New Eurofever/PRINTO classification criteria (EPCC) for Familial Mediterranean Fever (FMF) and other recurring fevers, as well as the pathogenicity of MEFV mutations, were recently created. The large multinational Eurofever FMF cohort assessed the impact of both the EPCC and INSAID pathogenicity categorization of MEFV mutations in real life. FMF patients in the Eurofever registry had their baseline demographic, genetic, and clinical data examined. The EPCC and the 2018 INSAID classifications for MEFV variations were used in all eligible FMF patients. Clinical data for 1,012 FMF (532 males/480 females, 827 children/185 adults) from 119 centers was accessible since November 2009. There were 887 individuals with complete data, 623 (70.2%) of whom satisfied EPCC (EPCC+), whereas 264 (29.8%) did not (EPCC−). The majority of EPCC− patients (172, or 65.1%) had genetics that was either negative or non-informative (monoallelic or biallelic benign variants, monoallelic variant of unknown significance). Colchicine was utilized in the majority of EPCC+ patients (88%) and a smaller number of EPCC patients (69%) at baseline (p<0.0001), who were treated with steroid or NSAID on demand (p=0.003 and 0.008, respectively). In addition, Anti-IL-1 therapy was given to 4% of the patients. When EPCC and the 2018 INSAID classification of MEFV variations were combined, 2 unique groups of patients could be identified, each with their clinical characteristics, therapeutic strategy, and treatment response. EPCC+ patients experienced FMF-like symptoms, but EPCC− patients had a more variable phenotype with a lower percentage of patients responding to colchicine.